Light weight composite material systems, polymeric materials, and methods

Abstract

The present invention relates to filled polymeric materials including a polymer and a filler distributed within the polymer, and to light weight composites which comprise at least a pair of metallic layers and a polymeric layer interposed between the pair of metallic layers, the polymeric layer containing the filled polymeric material. The composite materials of the present invention may be formed using conventional stamping equipment at ambient temperatures. Composite materials of the present invention may also be capable of being welded to other metal materials. The composite materials may be employed in an automotive part. Preferred composite materials include one or any combination of the following features: metallic fibers, ribbon fibers; or a polyolefin.

What is claimed is: 
     
       1. An automotive part comprising:
 a light weight composite material including a first metallic layer, a second metallic layer and a polymeric sheet of a filled polymeric material interposed between the first metallic layer and the second metallic layer, wherein the filled polymeric materials comprises:
 i. one or more polymers including a polyolefin polymer having a crystallinity of about 20 wt. % to about 80 wt. % as measured using differential scanning calorimetry and a melting point greater than about 100° C., as measured according to ASTM D3418-08; and 
 ii. a metallic filler; 
 
 wherein the automotive part has a coated face surface; and 
 an edge of the light weight composite material is sealed or includes a coating or a protective layer attached to the filled polymeric material; 
 the sheet is an extruded sheet having a thickness; 
 the metallic filler includes greater than 5 volume percent and less than 25 volume percent based on the total volume of the filled polymeric material of a mass of metallic fibers distributed within the polymer the mass spanning a thickness of the extruded sheet and including ribbon fibers having a weight average length greater than about 200 μm and less than about 25 mm; 
 the ribbon fibers have a width and a thickness, wherein the ratio of the width to the thickness of the ribbon fibers is about 3 or more; 
 the one or more polymers includes a second polymer, wherein the weight ratio of the second polymer to the polyolefin polymer is about 3:97 or more and about 40:60 or less; and 
 wherein the one or more polymers has a drop impact performance of about 100 g or more as measured according to ASTM D1790A at a thickness of 2 mil. 
 
     
     
       2. The automotive part of  claim 1 , wherein the coated face surface is an automotive class A surface. 
     
     
       3. The automotive part of  claim 1 , wherein the automotive part is an automobile panel, a truck panel, or an automotive bumper fascia. 
     
     
       4. The automotive part of  claim 1 , wherein the coated face surface is colored and includes a coating applied by electrocoating, a paint process, or a powder coat process. 
     
     
       5. The automotive part of  claim 1 , wherein the first metallic layer and the second metallic layer have different thickness. 
     
     
       6. The automotive part of  claim 1 , wherein
 a weight ratio of the one or more polymers to the metallic fibers is greater than about 2.2:1. 
 
     
     
       7. The automotive part of  claim 6 , wherein the ratio of the width to the thickness of the ribbon fibers is about 7 or more. 
     
     
       8. The automotive part of  claim 7 , wherein the one or more polymers has a melt flow rate of about 0.3 g/10 min or more and about 150 g/10 min or less, as measured according to ASTM D1238 at 190° C./2.16 kg. 
     
     
       9. The automotive part of  claim 1 , wherein
 the volume of the filled polymeric material is 30 volume % to 92% of the total volume of the light weight composite material, 
 the total thickness of the first and second metallic layers is from 5% to 70% of the total thickness of the light weight composite material; and 
 the polyolefin includes a polyethylene copolymer having at least 60% ethylene, a number average molecular weight greater than 20,000 and consists entirely of one or more α-olefins. 
 
     
     
       10. The automotive part of  claim 9 , wherein the coated face surface is an automotive class A surface. 
     
     
       11. The automotive part of  claim 9 , wherein the automotive part is an automobile panel, a truck panel, or an automotive bumper fascia. 
     
     
       12. The automotive part of  claim 9 , wherein the coated face surface is colored and includes a coating applied by electrocoating, a paint process, or a powder coat process. 
     
     
       13. An automotive part comprising:
 a light weight composite material including a first metallic layer, a second metallic layer and a polymeric sheet of a filled polymeric material interposed between the first metallic layer and the second metallic layer, wherein the filled polymeric materials comprises:
 i. one or more polymers including a polyolefin polymer having a crystallinity of about 20 wt. % to about 80 wt. % as measured using differential scanning calorimetry and a melting point greater than about 100° C., as measured according to ASTM D3418-08; and 
 ii. a metallic filler; 
 
 wherein the automotive part has a coated face surface; and 
 an edge of the light weight composite material is sealed or includes a coating or a protective layer attached to the filled polymeric material; 
 the sheet is an extruded sheet having a thickness; 
 the metallic filler includes greater than 5 volume percent and less than 25 volume percent based on the total volume of the filled polymeric material of a mass of metallic fibers distributed within the polymer the mass spanning a thickness of the extruded sheet and including ribbon fibers having a weight average length greater than about 200 μm and less than about 25 mm; 
 the ribbon fibers have a width and a thickness, wherein the ratio of the width to the thickness of the ribbon fibers is about 3 or more; 
 the one or more polymers includes a second polymer, wherein the weight ratio of the second polymer to the polyolefin polymer is about 3:97 or more and about 40:60 or less; and 
 wherein the polyolefin polymer has a crystallinity of 35% to 68%; and 
 the one or more polymers includes an elastomer having a tensile modulus at 100% elongation of less than 2 MPa and a tensile elongation at break of greater than 150%, both measured according to ASTM D638-08 at a nominal strain rate of 0.1 s −1 . 
 
     
     
       14. The automotive part of  claim 13 , wherein the coated face surface is an automotive class A surface. 
     
     
       15. The automotive part of  claim 13 , wherein the automotive part is an automobile panel, a truck panel, or an automotive bumper fascia. 
     
     
       16. The automotive part of  claim 13 , wherein the coated face surface is colored and includes a coating applied by electrocoating, a paint process, or a powder coat process.